This really depends on the design of the saddle and where the stirrups are
hung. If they are hung a little forward then the weight is thrown on front
part of the saddle which puts more stress on the horses's forehand.
>IMO "standing" is less stressful to the horse than posting because the
>rider's knees absorb the up-and-down motion of the horse's back, rather
>than the horse having to accelerate the rider up out of the saddle every
>other stride. It is this uneven stress (while posting) that necessitates
>changing diagonals periodically.
>
This is a good point. I tend to change between two point, posting and
cantering in order to spread the stress out - not to mention change muscle
groups being used.
Truman